With rapid development of touch-on-display technology, electronic devices provided with touch screens are widely used. Touch screens may be divided into several categories, such as pressure sensing touch screen, resistive touch screen, capacitive touch screen, infrared touch screen and surface acoustic touch screen, and the like. The capacitive touch screen is undoubtedly the most widely used touch screen, comprising transverse and longitudinal electrode arrays which are formed by ITO (indium tin oxide) material and cooperate with each other to form collectively a plurality of test points which are distributed uniformly on a surface of the screen, at intersection points where they intersect with each other. Since self-capacitance may be created among adjacent electrodes, then, variation of the self-capacitance at various test points may be acquired by a self-capacitance scanning, so as to implement a detection of a single touch. In addition, since mutual-capacitance may also be created among adjacent electrodes, then, variation of the mutual-capacitance at various test points may also be acquired by mutual-capacitance scanning, so as to implement a detection of a multi-touch.
A so-called “3D touch” is a stereoscopic touch technology which may enhance perception of both touch strength and touch area as compared with a multi-touch operation in a planar two-dimensional space. Nowadays, the 3D touch technology may only distinguish between two touch forms of “gentle/soft pressing” and “hard pressing” which differ from each other in degrees of strength of the applied pressure by touch operations, and thus has some difficulty in application thereof for detection of values of the pressure applied by touch operations and determination of touch position at which the touch operation is implemented, resulting in a difficulty in fine rating of the pressure applied by touch operations.